This invention relates to a method and apparatus for interconnecting electrical circuit elements. More particularly, this invention relates to a new and improved electrical connector and method of using the same for establishing electrical contact between a flexible circuit and another circuit device utilizing relative motion therebetween to wipe away any debris or other foreign matter (i.e., oxide films) which may adversely affect electrical contact.
Conventional methods of interconnecting electrical or electronic circuit components consist of the use of separate connector structures and/or soldering terminals on the components to conductors which deliver current to or from the components. With regard to the special case of flexible circuits, well known standard pin and socket connectors are typically employed to interconnect such flexible circuits to other electronic circuit components. While generally suitable for their intended purpose, standard pin and socket connectors do suffer from certain drawbacks and deficiencies. For example, standard pin and socket connectors typically do not provide adequate electrical performance, particularly for high speed electronic applications. In addition, standard pin and socket connectors often have a relatively complicated physical structure leading to high manufacturing costs, as well as a relatively large size leading to an undesirably high profile and an undesirable requirement for large circuit board area.
In some applications it has been found desirable to replace the use of standard pin and socket connectors as a technique for use in establishing connections to flexible and other circuits. In these applications, the requisite electrical contact may be established by mechanically pressing the terminal portions of the circuit against terminal pads on the connector, device or another circuit. Such prior art pressure connections are customarily made with the aid of a resilient pressure applicator, such as an elastomeric member, which is placed in compression to bias at least one of the components to be electrically interconnected toward the other component to hold the terminal portions thereof in electrical contract. Such a solderless connection system is disclosed in U.S. Pat. No. 4,468,074 assigned to the assignee hereof and incorporated herein by reference.
U.S. Pat. No. 4,468,074 discloses an apparatus wherein contact portions of a first array of conductive elements are urged against mating contacts of a second array of conductive elements by a pressure applicator comprising a resilient cellular plastic material thereby establishing and maintaining an electrical connection therebetween. The use of such a cellular resilient material permits a plurality of closely spaced exposed electrical conductors on or extending from a pair of substrates to be aligned and thereafter reliably pressed together, with the electrical connections being established by a requisite contact pressure applied to the substrates. The solderless connector of U.S. Pat. No. 4,468,074 may be employed to interconnect flexible circuits; to connect flexible circuits to circuits on rigid substrates; to establish connections between the leads extending from an integrated circuit in a circuit pattern on a flexible or rigid circuit board; and in other applications.
It is well known that conventional electrical connector devices, such as the male/female type, utilize mutual or relative sliding motion during the connecting process. This relative motion between the cooperating male and female connectors is desirable as it acts to "wipe" away any debris or foreign matter on the connectors. Such debris may adversely effect electrical contact. While suitable for its intended purposes, the solderless connector or U.S. Pat. No. 4,468,074 will not necessarily provide such relative motion between the flexible circuit and other circuit devices which are to be interconnected. This is because the circuit devices are interconnected when one device is brought down and disposed on another device thereby precluding any lateral movement which would act to wipe away undesirable foreign matter. Consequently, dirt debris and other foreign matter may still be present on the respective electrical contacts subsequent to interconnection which may lead to unreliable contacting.
Another area of concern with "non-wiping" solderless connectors of the type disclosed in U.S. Pat. No. 4,468,074 is the open aging of the circuits before assembly. During exposure to the normal levels of corrosive gases common in air, the metal contact surfaces can corrode, reducing the electrical performance when assembled. As mentioned hereinabove, a typical method for improving the performance of connectors is to provide for a sliding motion between the contacts as they are mated. This sliding action breaks through the nonconductive corrosion layers that may have formed and thus improves the electrical performance of the connector.
U.S. Pat. No. 4,717,345, which is assigned to the assignee hereof, discloses several embodiments of a solderless connector that effectively "wipes" away any debris or foreign matter on the connector contacts. A male/female connector assembly is depicted in FIGS. 2-5 of U.S. Pat. No. 4,717,345. Unfortunately, this particular connector assembly suffers from certain drawbacks and deficiences. For example, the connector of FIGS. 2-5 is difficult to assemble and disassemble, lacking precise and easy means for connecting the flexible circuit to the male insert portion.
Still other prior art solderless connectors are disclosed in U.S. Pat. Nos. 4,647,125; 4,655,524; 4,744,764 and 4,768,971.